Speed-changing mechanism.



No. 665,355 Patented Jan. I, I90l. A. S. WILLIAMS.

SPEED CHANGING MECHANISM.

(Appl a nflldHyQU 1899) 2 Shoots-Sheet I (No Model.

No. 665,355. Patented Jan. I, I90l. A. S. WILLIAMS.

SPEED- CHANGING MECHANISM.

(Application filed May 25. 1899.] Modem 2 Sheets8heet z.

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ARTHUR S. WILLIAMS, OF NEWTON, MASSACHUSETTS, ASSIGNOR TO THE CONSOLIDATED MACHINE SPECIALTY COMPANY, OF BOSTON,

MASSACHUSETTS.

SPEED-CHANGING MECHANISM.

SPECIFICATION forming part of Letters Patent No. 665,355, dated January 1, 1901.

Application filed May 25, 1899. Serial No. 718,210. (No model.)

/ of Newton,county of Middlesex, State of Massachusetts, have invented an Improvementin S peed-Changin g Mechanism, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to mechanism adapted to be interposed between a prime motor or driving device and apparatus to be driven whereby the speed of the latter may be varied according to the work to be done.

Various novel features of myinvention will be hereinafter described in the specification,

and particularly pointed out in the claims. My invention belongs to that general type of speed-changing mechanism wherein the driving and driven members are provided on their opposed faces with annular grooves, friction-wheels being interposed between said members and adapted to engage their grooved faces, the variations in the position of the friction wheel or wheels relative to the said driving and driven members operating to vary the relative speed of such members.

Figure 1 is a partial top or plan View of one form of apparatus embodying my invention, the driving and driven members being shown in horizontal section; Fig. 2, a vertical longitudinal section of the apparatus shown in Fig. 1, taken on the line a; thereof; Fig. 3, a horizontal sectional View of a modification to be described. Figs. 4 and 5 are vertical and partial longitudinal sections of other modified forms of my invention, and Fig. 6 is a vertical sectional detail of the foot of the friction-wheel support and the boss on which it rocks. It is a very common practice to directly connect an electric or other motor with the apparatus to be driven thereby-such as a lathe, sewing-machine, printing-press, &c.and as my present invention is particularly adapted for use in such connection I have in Figs. 1 and 2 shown a construction arranged for connection and cooperation with an electric motor, the casing of the latter being indicated at M, Fig. 1, suitably bolted, as at m to the base B of the frame, on which the operative parts of the speed-changing mechanism are mounted. The said base is herein shown as provided with uprights B B which at their upper ends form extended bearings B B for the elongated hub C of the member C to be driven, the bearings having suitable caps. V

The member C is herein shown as provided on its inner face with an annular groove C, the cross-section of which is a circular arc struck from the point 30, Fig. 2, said member having a peripheral flange 0 which may be used to transmit power, if desired.

The hub C is provided with an internal annular flange or projection c, Fig. 2, and, as shown in Figs. 1 and 2, one member, as f, of an end-thrust ball-bearing bears against the outer end of the hub O a series of antifriction-ballsy beingheld by a suitable cage f between the partf and the part f of said hearing.

I have herein shown the armature-shaft M of the motor as extended loosely through the hub C and shouldered at m just beyond the flange c, the shaft being reduced in diameter beyond said shoulder and extending through a bushing or lining c of babbitt or other suitable antifriction metal, said shaft also extending through the thrust-bearing and beyond the latter and preferably threaded at its outer end, as at m, to receive thereon an adjustable collar m and, if desired, a checknut m. A strong coil-spring S is interposed between the collar m and the thrust-bearing, the expansive action of the spring normally forcing the bearing against the end of the hub and at the same time tending to move the shaft M to the right, viewing Fig. 1. The shaft has no endwise movement; but the hub of the driven member C is permitted slight longitudinal movement, so that the tendency of the spring is to force said member to the left, viewing Fig. 2.

The driving member D is herein shown as disk-like and mounted upon and rigidly secured to the shaft M in any suitable inanner, the inner face of the driving member having an annular groove D therein, the crosssectional curvature of which is struck from the center 30.

Referring to either Fig. 1 or Fig. 2, it will be manifest that there is a great difference in the sizes of the members D and C, the former being very much the smaller, and this construction, with the eccentric or differential mounting of the interposed friction wheel or wheels, to be hereinafter described, enables me to materially reduce the cost of construction of the apparatus without unduly limiting its scope.

The width of the groove D is very small compared with the width of the groove C, and in actual practice the groove D may be formed with a single cutting-tool, whereas the large groove in the member 0 not only takes more time to form, but it must be done with much greater expenditure of care and skill. Inasmuch as the radii of the cross-sectional curvature of the grooves G and D vary so materially, it is necessary to provide for differential movement of the friction wheel or disk interposed between the members D and C. One or more friction disks or wheels E are located between the driving and driven members, the axle e of each disk or wheel being mounted in a yoke-like support if, having its foot t laterally offset or eccentric to the wheel-axis, as clearly shown in Fig. 2, said foot having an elongated hole 15 through it (see Figs. 1, 2, and 6) to receive loosely a stud to which the yoke-like support is connected by a transverse pivot-pin t the lower end of the stud t passing through a boss B on the frame of the apparatus and having attached to it a segmental gear T, Fig. 1. The under side of the foot is rounded, as at 15 (see dotted lines, Fig. 2,) to rest in a correspondingly-shaped socket in the top of the bearing B the part Z and its socket being shown in section very clearly in Fig. (3, wherein it will be seen that the elongated hole 25 extends down through the rounded portion t In the latter figure two disks or friction-wheels E are shown, and their segment-gears T intermesh, so that the oscillating or turning movement of the supports about their fulcra will be simultaneous, but in opposite directions. This movement may be con veniently effected in any suitable manner, and in the present case I have shown in Fig. 1 a supplemental segment T, attached to one of the fulcrumstuds 15 in engagement with a pinion T mounted on the frame of the apparatus and provided with an actuating-handle T movement of the latter in one or the other direction tending to swing the friction-wheels on their fulcra. In Fig. 1 said wheels are shown in parallelism and parallel to the shaft M and consequently the member C would be rotated at the same speed as the driving member D. From this position to the extreme outward position (shown by the broken lines in Fig. 1) the speed of the driven member 0 may be gradually decreased relative to the speed of the driving member, and it will be seen that the fulcrum 15 on which a frictionwheel is turned and which is eccentric to its own axis of rotation, substantially coincides with the common center of curvature 30, Fig. 2, of the two annular grooves D C.

In Fig. 3 the grooves in the driving and driven members L and L, respectively, are made wider than the grooves shown in Fig. 1, or, in other words, the arc of curvature in cross-section is longer; but said arcs, while of different radii, are struck from a common center, as 35, and the friction-disks E are mounted, as hereinbefore described, eccentric to their own axes of rotation. It will he noticed, however, that on comparing Fig. 3 with Fig. l the range of movement of the friction-wheels in the former is double that of the latter, and that while in the construction shown in Fig. 1 the speed of the driven membercan be varied between the same speed as the driving member and a lower speed, in the construction shown in Fig. 3 the speed of the driven member can be increased or decreased relative to that of the driving member. The advantages of construction hereinbefore set forth as to the construction shown in Fig. l are, however, presentiu the construction shown in Fig. 3, though to a somewhat less degree.

The mounting of the friction-wheel as herein set forth brings the weight of the same and the greater part of its support if to that side of the transverse pivot 15 opposite the driving member, so that when the driving and driven members are separated in any usual manner the support will rock automatically on its transverse pivot to throw the wheel out of engagement with the driving member.

While the power may be transmitted to the apparatus to be driven directly from the driven member 0, I prefer to mount a pulley or other transmitting member, as I, Figs. 1 and 2, on the hub 0 to rotate therewith, and in said figures the pulley is shown as located between the bearings B B and from inspection of these figures it will be manifest that the two bearings referred to provide a large supporting-surface for the hub, so that there is practically no chatter or vibration when the mechanism is running and the parts are supported in a very strong and durable manner. The bearings B and B are shown in Fig. 2 as provided with oil-reservoirs 10, from which the oil is lifted to the exterior of the hub C by means of loose rings 12 of wellknown construction.

The construction shown in Figs. 1 and 2 is particularly adapted for use with electric motors, and it is to be noted that in the use of motors the stoppage of the apparatus to be driven is effected by or through the stoppage of the motor, so that there is no occasion to provide means for effecting the separation of the driving and driven members D O. In fact, in this construction the spring S tends to always maintain said members in engagement with the friction wheel or wheels E.

A modification is shown in Fig. 4:, the hub A of the driven member A being supported in a single bearing 13, and at its outer end said hub is provided with a laterally-extended flange 0b, to which may be attached a powertransmitting pulley P The shaft G to which the driving member G is splined, as at g, is extended through the hub A and said shaft is at its outer end beyond the hub passed through an end-thrust ball-bearin g F*, substantially such as shown more clearly in Fig. 2, one'part of said bearing resting against the end of the hub, while the other member is engaged by a retaining-nut a on the end of the shaft. A collar g only one-half of which is shown in Fig. 4, is secured to the shaft G and between said collar and the driving member G is interposed a strong spring S. The friction wheel or disk E may be of the construction hereinbefore referred to. The spring acts to force the driving and driven members together, as will. be manifest from the drawings.

Still another modification is shown in Fig. 5, wherein the hub H of the driven member H is passed through a bearing B said hub having an internal shoulder h against which rests a thrust-bearing F the shaft K, to which the driving member (not shown) is attached, passing through a babbitt lining la and through the thrust-bearing, the extremity of shaft, which is not in this instance carried beyond the hub, being provided with a collar 70' and a check-nut 70 with a strong spring S interposed between the collar and the thrust-bearing.

By any suitable form of coupling, as h a pulley or other suitable transmitting member P may be attached to the end of the hub. The power-transmitting member, therefore, may be connected with and to rotate with the driven member H, different modes of attachment being herein shown.

My invention is not restricted to the precise construction and arrangement of parts herein shown, as the same may be modified or rearranged in various particulars without departing from the spirit and scope of my invention.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. Speed-changing mechanism comprising a driving member and a member to be driven arranged in axial alinement, the opposed faces of said members having annular grooves therein of different cross-sectional radii, a friction-wheel between and adapted to engage the grooved faces of said members, and means to support said wheel and to turn it on a fulcrum eccentric to its own axis, to vary the relative speed of the driving and driven members.

2. Speed-changing mechanism comprising a driving member and a member to be driven arranged in axial alinement, the opposed faces of said members having annular grooves therein of diiferent cross sectional radii struck from a common center, a frictionwheel between and adapted to engage the grooved faces of said members, and means to support and turn the Wheel on a fulcrum eccentric to its own axis of rotation and intersecting the common center of cross-sectional curvature of said grooves.

3. Speed-changing mechanism comprising a driving member, and a member to be driven in axial alinement and their opposed faces having annular grooves therein of different cross-sectional radii, a plurality of frictionwheels between and adapted to engage the grooved faces of said members and means to support said wheels and to turn them simultaneously on fulcra eccentric to their own axes of rotation, to change positions of said wheels relative to the peripheries of the grooved members and thereby vary the relative speed of the latter.

4. Speed-changing mechanism comprising a driving member, its attached shaft, a member to be driven coaxial with and independent of said shaft, the opposed faces of said members having annular grooves therein of different cross sectional radii, a frictionwheel between and adapted to engage the grooved faces of said members, meansto support said wheel and to turn it on a fulcrum eccentric to its own axis, independent bearings for said driving and driven members, and means, including an end -thrust ballbearing and a spring, to maintain said members and the friction-Wheel in engagement.

5. Speed-changing mechanism comprising a driving member and a member to be driven, the opposed faces of said members having annular grooves therein, a friction-wheel between and adapted to engage the grooved faces of said members, means to support said wheel and to-turn it on a fulcrum eccentric to its own axis, and a lateral connection between said support and fulcrum, upon which connection the wheel may rock by gravity.

6. Speed-changing mechanism comprising a driving member, its attached shaft, a member to be driven coaxial with and independent of said shaft, the opposed faces of said members having annular grooves therein of difierent crosssectional radii, a frictionwheel between and adapted to engage the grooved faces of said members, means to support said wheel and to turn it on a fulcrum eccentric to its own axis, independent bearname to this specification in the presence of two subscribing witnesses.

ARTHUR S. WILLIAMS.

Witnesses:

JOHN C. EDWARDS, AUGUSTA E. DEAN.

IIO 

